Magnetism in semiconducting molybdenum dichalcogenides

Transition metal dichalcogenides (TMDs) are interesting for understanding the fundamental physics of two-dimensional (2D) materials as well as for applications to many emerging technologies, including spin electronics. Here, we report the discovery of long-range magnetic order below T _M = 40 and 100 K in bulk semiconducting TMDs 2H-MoTe₂ and 2H-MoSe₂, respectively, by means of muon spin rotation (μSR), scanning tunneling microscopy (STM), and density functional theory (DFT) calculations. The μSR measurements show the presence of large and homogeneous internal magnetic fields at low temperatures in both compounds indicative of long-range magnetic order. DFT calculations show that this magnetism is promoted by the presence of defects in the crystal. The STM measurements show that the vast majority of defects in these materials are metal vacancies and chalcogen-metal antisites, which are randomly distributed in the lattice at the subpercent level. DFT indicates that the antisite defects are magnetic with a magnetic moment in the range of 0.9 to 2.8 μ_B. Further, we find that the magnetic order stabilized in 2H-MoTe₂ and 2H-MoSe₂ is highly sensitive to hydrostatic pressure. These observations establish 2H-MoTe₂ and 2H-MoSe₂ as a new class of magnetic semiconductors and open a path to studying the interplay of 2D physics and magnetism in these interesting semiconductors.

Cluster of TRIM genes in the human MHC class I region sharing the B30.2 domain

The major histocompatibility complex (MHC), a region of high gene density, contains a large number of genes relevant to the immune response, belonging to different multigenic families. We studied the genomic organization and polymorphism of a set of genes in the MHC class I region containing the tripartite motif (TRIM), consisting of a RING domain, B-box and coiled coil region, and a B30.2-like domain. A cluster of seven genes at 6p21.33 and two related family members telomeric of the cluster were characterized. All MHC-encoded TRIM-B30.2 genes showed moderate levels of polymorphism, affecting predominantly the RING and B-box domains. In terms of structure, the genes varied by the loss of partial and, in some cases, complete domains. They were strongly conserved in exons 2, 3 and 4, which form the coiled-coil region. The last exon, encoding the B30.2-like domain, is shared with the otherwise unrelated butyrophilin-like (BTN) genes, located 4.3 Mb telomeric of the TRIM-B30.2 cluster. The data are consistent with multiple, ancient duplications giving rise to a set of related genes.

Genetics and molecular genetics of the MHC

The MHC is a well-characterised region of the human genome, containing a high diversity of genes and an apparent clustering of genes involved in the immune response. The genomic sequence of an 8 Mb section, containing the MHC and flanking regions and covering over 300 genes, will soon be available. Since this is a highly polymorphic region, the molecular genetics of the MHC and its relationship with disease have been studied in considerable detail.

Childhood farm injuries in Old-Order Amish families

Unintentional injuries are the leading cause of death and disabilities in the United States among children, with the incidence even greater among children who live on a farm. Information exists about farming accidents on mainstream U.S. farms; however, little is known about the Amish farms. The purpose of this study was to investigate injuries among Old-Order Amish in Pennsylvania. Teachers in Amish schools were surveyed about their experiences with accidents/injuries among children on the farm. Seventy percent of the teachers reported a childhood farm injury in their family, with the majority attributing this to farm animals. Injuries may be preventable if age-appropriate tasks are assigned to children and they are properly supervised.

The cluster of BTN genes in the extended major histocompatibility complex

We sequenced the 170-kb cluster of BTN genes in the extended major histocompatibility complex region, 4 Mb telomeric of human leukocyte antigen class I genes, at 6p22.1. The cluster consists of seven genes belonging to the expanding B7/butyrophilin-like group, a subset of the immunoglobulin gene superfamily. The main complex is composed of six genes, from two subfamilies, BTN2 and BTN3, arranged in pairs. This alternating pattern must have evolved by duplications of an original block of two genes, one from each subfamily. The sequences from the two subfamilies share approximately 50% amino acid identity. By analysis of repeat elements within each block, these duplications may be dated to approximately 100 million years ago, at about the time of the branching of the Rodentia and Primate lineages. The single BTN1A1 (butyrophilin) gene was positioned approximately 25 kb centromeric to the cluster. Each gene covers approximately 12 kb and consists of seven (BTN2 subfamily) or nine (BTN3 subfamily) coding exons. The predicted leader sequence, immunoglobulin-like IgV (variable)/IgC (constant) ectodomains, and the predicted transmembrane domain are encoded on separate exons and are separated from a B30.2 domain by a variable number of very short exons, 21 and 27 nucleotides in length. BTN transcripts were detected in all tissues examined. Alternative splicing, involving particularly the carboxyl-terminal B30.2 domain, was a notable feature. Most transcripts of BTN2 subfamily genes contained this domain, whereas BTN3 genes did not. Using immunofluorescence, we showed surface expression of BTN-green fluorescent protein fusions in mammalian cell transfectants.

Renovating existing space to meet special needs for outpatient paediatric oncology

Many existing hospital buildings are inadequate to meet needs caused by a tremendous shift from inpatient to outpatient care. Expensive diagnostic and treatment facilities must still be shared by inpatients and outpatients, which in many cases makes renovations to existing facilities on site more appealing than new free-standing facilities; However, care must be taken in the planning and design to make sure that existing hospital operations can be maintained throughout this work. St. Jude Children's Research Hospital in Memphis, an internationally acclaimed institution devoted to the research and treatment of catastrophic illnesses in children has experienced a large growth in its outpatients' care due mainly to changes in treatment modalities and the development of more effective cures. The result has been an extreme overcrowding and unpleasant experiences for patient and family due to awkward patient flow and work processes attempting to respond to the inadequate facility conditions. This paper will not only review the planning issues, but will discuss the renovation which will require several phases in order to minimise disruption to the ongoing activities.

The perception of farm safety and prevention issues among the Old Order Amish in Lancaster County, Pennsylvania

The purpose of this study was to explore farm safety and prevention issues within an Old Order Amish community. A qualitative ethnographic approach was used to explore perceptions of Amish adults as to the issues related to farm safety and prevention for their children. Access to this community was facilitated through two contact people who were well known in the community. Data were collected using semistructured interviews and recorded as field notes. Data analysis was done by looking for themes based on the questions asked about safety and prevention. From this analysis, four themes were found related to safety and prevention. They included education of the parents, education of the children, home and farm preventive measures, and enforcement of established rules. In addition, childhood readiness was found to be another important issue related to farm safety. Childhood readiness was found to have three themes, developmental appropriateness, parental control and supervision, and birth order of the child. Data from this study suggested that farm safety is a concern of the Old Order Amish in Lancaster County. Their perceptions of safety and prevention issues centered on the incidents that have occurred and are considered dangerous. It is important to look at the identified safety and prevention and childhood readiness themes to identify the most beneficial approaches for the Amish to promote safety on their farms.

Complex duplications at 6p22.1, 6p11.2, 5q13, 5p15.1 and 5p13 revealed by fluorescent in situ hybridisation

A complex pattern of fluorescent in situ hybridisation (FISH) has been detected using PAC clones from the short arm of chromosome 6, proximal to the haemochromatosis gene at 6p22.1. Cross-hybridisation to 6p22.1, 6p11.2, 5q13, 5p15.1 and 5p13 was consistently detected with several PAC clones covering a genomic region greater than 200 kb. These results indicate that large sections of genomic DNA are shared by these 5 disparate chromosomal segments, indicative of large scale duplication events. These results were in part accounted for by the identification of several expressed sequence tags (ESTs).

Hereditary juvenile haemochromatosis: a genetically heterogeneous life-threatening iron-storage disease

Juvenile haemochromatosis is a rare inborn error of iron metabolism with clinical manifestations before 30 years of age. Unlike adult haemochromatosis which principally affects men, juvenile haemochromatosis affects the sexes equally; it causes early endocrine failure, dilated cardiomyopathy and joint disease. We report four patients (two of each sex) from three pedigrees affected by juvenile haemochromatosis with a mean onset at 22 years (range 14-30). All had endocrine deficiency with postpubertal gonadal failure secondary to pituitary disease; two suffered near-fatal cardiomyopathy with heart failure. Mean time to diagnosis from the first clinical signs of disease was 9.8 years (range 0.5-20) but general health and parameters of iron storage responded favourably to iron-depletion therapy. A 24-year-old man listed for heart transplantation because of cardiomyopathy [left ventricular (LV) ejection fraction 16%] responded to intravenous iron chelation with desferrioxamine combined with phlebotomy (ejection fraction 31%). A 27-year-old woman with subacute biventricular heart failure refractory to medication required orthotopic cardiac transplantation before the diagnosis was established (LV ejection fraction 25%). Genetic studies showed that these two patients with cardiomyopathy from unrelated families were heterozygous for the HFE 845G-->A (C282Y) mutation and wild-type at the H63D locus: complete sequencing of the intron-exon boundaries and entire coding sequence of the HFE gene failed to identify additional lesions. Two siblings in a pedigree without cardiomyopathy were wild-type at the HFE C282Y locus; although the brother harboured a single copy of the 187C-->G (H63D) allele, segregation analysis showed that in neither sibling was the iron-storage disease linked to MHC Class I markers on chromosome 6p. Juvenile haemochromatosis is thus a genetically heterogenous disorder distinct from the common adult variant.

Design of the New East Hospital (Shanghai, People's Republic of China)

We feel very fortunate to have been involved in the project at East Hospital. Because the clientele is so vastly different in China, JMGR has been challenged to produce a facility that is extremely design oriented, giving us an opportunity to push the limits of design and aesthetics to create a unique solution to project opportunities. Our clients at East Hospital are eager to possess a contemporary building that demonstrates their commitment to progress. They desire a building that makes a statement about their country's entry into the global marketplace. We believe the design of East Hospital encompasses these client desires, while at the same time, elevates the facility to meet modern international standards. Our work at East has, in turn, led to the involvement with other Chinese clients. Today, JMGR has a total of six projects either completed or under design in China.

Homozygosity for the predominant Cys282Tyr mutation and absence of disease expression in hereditary haemochromatosis

A candidate gene for hereditary haemochromatosis, HLA-H, has recently been presented. Two missense mutations in the HLA-H gene sequence are predicted to account for nearly 90% of all cases of the disease. The aim of this study was to correlate the presence of these missense mutations with the expressivity of the disease, as assessed by standard biochemical evaluation of serum iron parameters. Detection of the known mutations in haemochromatosis, Cys282Tyr and His63Asp, was undertaken in a large pedigree showing variable expression of the disease in successive generations. In three sibs with overt disease (one male, two female, aged 50 to 53 years), homozygosity for the predominant G to A transition (Cys282Tyr) in HLA-H was detected. However, homozygosity for this mutation was also detected in an asymptomatic male sib, aged 50, harbouring an identical genotype. The finding of an asymptomatic homozygous Cys282Tyr subject, haplo-identical to affected sibs, indicates that clinical expression of symptomatic disease is variable, even in middle aged Cys282Tyr homozygotes. This has profound implications for the future use of genetic screening for haemochromatosis.

Assignment of the human ferrochelatase gene (FECH) and a locus for protoporphyria to chromosome 18q22

We have mapped the human gene for ferrochelatase (FECH; ferroheme-protolyase, EC 4.99.1.1) to chromosome 18 by hybridization of cDNA to sorted chromosomes. The probe was obtained by PCR-directed amplification of a human marrow cDNA library in lambda gt 10. Subchromosomal localization of ferrochelatase to 18q22 was determined by chromosomal hybridization in situ using a human ferrochelatase genomic clone in lambda EMBL 3 that contained a 20-kb insert. Since ferrochelatase activity is deficient in patients with the inherited disease erythropoietic protoporphyria, a locus for this disease may be assigned to 18q22, one of few monogenic defects that have been mapped to this chromosome.